Spend $50, Ship Free Anywhere
The Emerald Mithrax Crab is a commonly kept crustacean and is widely known for its ability to help control outbreaks of bubble algae in reef aquariums. These crabs are, however, omnivorous and will not hesitate to help clean up any excess or leftover meaty foods or waste that can settle on or in various surfaces of the tank. Emerald Crabs tend to stay hidden away during the day, emerging from small crevices or ledges to hunt and scavenge for algae and other debris at night. Although generally peaceful, in the absence of sufficient food, Emerald Crabs may demonstrate opportunistic behavior and attempt to predate on smaller invertebrates, fishes, and sometimes corals, so it is imperative to keep them well fed in established systems.
Emerald crabs (Mithraculus sculptus) are hardy, algae-eating invertebrates that play a crucial role in controlling nuisance algae in reef aquariums. Known for their bright green exoskeleton and powerful claws, these scavengers specialize in consuming bubble algae (Valonia spp.), making them a valuable addition to any cleanup crew.These crabs are low-maintenance and adaptable, often seen climbing rock structures or hiding in crevices during the day before emerging to scavenge at night.
Care Level: Easy – Adaptable and low-maintenanceMinimum Tank Size: 10+ gallonsAquarium Setup: Requires ample rockwork for hiding and foragingEmerald crabs are nocturnal scavengers, spending most of the day hiding in rock crevices before emerging at night to graze on algae and organic debris.
Emerald crabs are omnivorous and require a varied diet to thrive.Diet: Omnivorous – Prefers algae, detritus, and leftover foodRecommended Foods:Bubble algae (primary natural food source)Hair algae, film algae, and uneaten fish foodSupplemental seaweed and algae-based pellets if algae is scarceIf food becomes limited, emerald crabs may opportunistically scavenge, so regular supplemental feeding ensures they remain reef-safe.
Lifespan: 2-4 yearsGrowth Rate: Moderate – Typically reaches 2 inches acrossAs they grow, emerald crabs shed their exoskeleton through molting, which is a natural process that may make them appear vulnerable for a short time.
Temperament: Peaceful to Semi-Aggressive – Generally peaceful but may show territorial behavior if underfedReef Safe? With Caution – Completely safe for corals but may prey on small invertebrates if hungryAvoid housing them with aggressive crabs, triggerfish, puffers, or large wrasses, as these species may harass or eat them.
Opportunistic Feeding: If food is scarce, they may target small shrimp or slow-moving invertebrates.Territorial in Small Tanks: Best kept in larger systems with plenty of food and hiding spots.Molting Vulnerability: Newly molted crabs hide until their shell hardens, reducing visibility for a short period.To ensure safe and effective cleanup, provide a well-established tank with algae and detritus.
Temperature: 74-80°FdKH (Alkalinity): 8-12pH: 8.1-8.4Specific Gravity: 1.024-1.026
For all orders exceeding a value of 100USD shipping is offered for free.
Returns will be accepted for up to 10 days of Customer’s receipt or tracking number on unworn items. You, as a Customer, are obliged to inform us via email before you return the item.
Otherwise, standard shipping charges apply. Check out our delivery Terms & Conditions for more details.
